[Freeipa-users] Very slow kerberos performance after upgrade to IPA 2.2

[Sigbjorn Lie]

Hi,

I've been having performance issues after I upgraded to RHEL 6.3 / IPA 
2.2. I still have a LDAP server having unusual high cpu usage even after 
it's been removed from the SRV records and is serving almost no clients 
anymore, but it would seem as my main issues is with the kerberos server.

All kerberos services are performing very slowly, and the IPA servers 
has much higher CPU load now then what they had with IPA 2.1. Some 
services are timing out, like kerberized web servers, other kerberized 
services perform authentication very slowly. I had to switch our 
automounter away from kerberos authentication as it is no longer usable.

Using SSH to log on to SSSD enabled hosts are also very slow, a login 
takes anything from 5 seconds up to 20 seconds. Noticably longer than 
pre IPA 2.2.

The IPA web admin interface is definitely not faster than in IPA 2.1.

For a comparison, listing out all the folders in an automount map, 
causing them to be looked up from LDAP and mounted takes over 5 minutes 
with IPA 2.2 when using kerberos authentication for the automounter. 
There are approx 130 folders in that automount map.

After unmounting all the mounted folders, and changing to using a 
username and password authentication with a TLS connection, attempting 
the same operating again, and it now finishes in about 14 seconds for 
both the lookup from LDAP and the mount operation.

After unmounting all the mounted folders again, changing to username and 
password authentication with a simple unencrypted bind, and then 
attempting the same operation and it now finishes both lookup and mount 
in just over 5 seconds!

I don't have any timing for kerberized automount pre IPA-2.2, but we 
we're not talking about several minutes to mount all the folders in this 
automount map. Unfortunately mounting all the folders is what happens 
when the users use konqueror to browse the automount maps, so this is a 
very noticable issue.

Even loading a new gnome-terminal or konsole terminal which causes an 
automount folder to be mounted takes anything between 5 - 15 seconds 
after the upgrade. There we're no notiable delay when opening a new 
terminal window pre IPA-2.2.

I am not using SSSD for the automounter.

I do notice that the dbmodule for the kerberos server has changed from 
"kldap" to "ipadb.so" Perhaps there is some issues with the new library?




Regards,
Siggi